Shock absorption pad for a vehicle

ABSTRACT

The present invention the related to a shock absorption pad for a vehicle for protecting occupant&#39;s lower legs. The shock absorption pad according to the present invention on which an occupant&#39;s foot is placed is attached on a surface of a toe board. The shock absorption pad includes a first shock absorption layer provided on the occupant&#39;s foot-placing side for absorbing an impact generated in a boundary region at which an energy absorption load of a vehicle body becomes different in a deformation process of the vehicle body at a vehicle crash, and a second shock absorption part provided on the toe board&#39;s side for absorbing an impact generated in a region in which the energy absorption load is high.

TECHNICAL FIELD

The invention relates to a shock absorption pad for use in a vehicle forprotecting occupant's lower legs at the time of a vehicle crash, andmore specifically relates to a shock absorption pad for use in a vehiclehaving a stepwise shock absorption characteristic.

BACKGROUND ART

Concerning the structure for protecting occupant's lower legs, JP,2000-103367, A and JP, 2000-326870, A disclose inventions, wherein thestructure of a vehicle itself is configured to have the desired shockabsorption characteristic. Further, JP, 5-330341, A and JP, 6-17097, B,disclose inventions, wherein the foam material that absorbs energy isarranged in foot resting portions in the cabin so as to protect theoccupant's lower legs.

However, giving a desired shock absorbent function to the structure ofthe vehicle itself involves design changes of vehicle body structure andmay require additional material and parts to achieve the desired shockabsorbent function. So it is predicted to increase the cost.

Moreover, in the case of using a shock absorption material, such as afoam material, since the shock absorption characteristic is fixed, theimpact load whose magnitude varies in the deformation process of thevehicle body at the time of a vehicle crash cannot be absorbedeffectively.

The energy absorption load of the vehicle in the deformation process atthe time of a vehicle crash is highly set up in a rear portion of afront side member rather than in a front portion of the front sidemember, or is highly set up in an inclined portion that extends from therear end of the front side member backward and downward along thesurface of a toe board of a lower dash panel.

Therefore, the deceleration that acts on the vehicle body becomessuddenly high for a short time interval in the boundary region where theenergy absorption load in the rear portion or the inclined portionchanges in the direction that becomes high. Then, the rear portion orthe inclined portion will deform under the set-up energy absorption loadto absorb energy.

In this case, the vehicle after the crash can be stopped by virtue ofthe high energy absorption load due to the deformation of the rearportion or the inclined portion. At this time, the impact on occupant'slower legs can be reduced by shock absorption material, such as a foammaterial. However, it is difficult to achieve adequate compatibilitybetween this reduction and the reduction of the impact force whichbecomes suddenly high for a short time interval in the boundary regionat which the energy absorption load of the vehicle body changes.

For the solution to this problem, it is conceivable that by changing thestructure of the vehicle body, the energy absorption load difference ismade small so as to attain the smooth energy absorption loadcharacteristic. However, this will result in increased manufacturingcost of the body structure.

DISCLOSURE OF INVENTION

It is a general object of the present invention to provide a shockabsorption pad for use in a vehicle that can reduce more effectively thevarious shocks applied to occupant's lower legs without significantlychanging the body structure.

A more specific object of the present invention is to provide the shockabsorption pad for a vehicle, which is equipped with the shockabsorption characteristic configured to be variable in a multi-steppedmanner according to the various shocks that act on occupant's lowerlegs, whereby the shock applied to occupant's lower legs can be reducedmore effectively.

In order to achieve the above-mentioned objects, there is providedaccording to the present invention a shock absorption pad for a vehiclewhich is attached on a surface of a toe board and on which an occupant'sfoot is placed, comprising: a first shock absorption part provided onthe occupant's foot-placing side for absorbing an impact force generatedin a boundary region at which an energy absorption load of a vehiclebody becomes different in a deformation process of a vehicle body at avehicle crash; and a second shock absorption part provided on the toeboard's side for absorbing an impact generated in a region in which theenergy absorption load is high.

According to this arrangement, since the shock absorption pad isprovided with two shock absorption parts whose shock absorptioncharacteristics are different from each other, different types of impactloads applied on occupant's lower legs, which are generated in thecourse of a vehicle body's deformation process, can be effectivelyreduced by these two shock absorption parts, respectively. That is, theimpact, which becomes suddenly high for a short time in the boundaryregion in which the energy absorption load of vehicle becomes different,can be absorbed by the deformation of the first shock absorption part,whereby the shock over occupant's lower legs which is likely to becomemomentarily high can be reduced. Then, the impact generated second inthe region in which the energy absorption load of the vehicle bodybecomes high can be absorbed by the deformation of the second shockabsorption part, whereby the shock over occupant's lower legs can bereduced. Especially, since the first shock absorption part is providedon the side on which occupant's legs may be laid, the shock absorptioncharacteristic can easily be tuned so that it adapts to the impact thatreaches its peak suddenly for a short time in the boundary region inwhich the energy absorption load of vehicle becomes different.

It is noted that the above-mentioned shock absorption pad has thecharacteristic such that an amount of deformation per unit load in adirection perpendicular to the surface of the toe board is lower in thesecond shock absorption part than in the first shock absorption part.

Further, according to the shock absorption pad, wherein the first shockabsorption part is divided in a plane over the occupant's foot-placingarea so as to lower an in-plane rigidity of the first shock absorptionpart during its compressive deformation, and an energy absorption loadper unit area of the first shock absorption part is set lower than thatof the second shock absorption part, it becomes possible to form theshock absorption parts whose shock absorption characteristics aredifferent from each other. That is, as the result of lowering anin-plane rigidity of the first shock absorption part, the first shockabsorption part becomes easy to deform in a good follow-up manner enoughto absorb the impact that reaches its peak suddenly for a short time inthe boundary region of the energy absorption load of vehicle body,whereby the respective shocks over occupant's lower legs can beadvantageously absorbed, respectively.

Further, according to the shock absorption pad, wherein the first shockabsorption part is comprised of a plurality of projections formed allover the occupant's foot-placing area on an upper surface of the secondshock absorption part, it becomes possible to advantageously absorb therespective shocks over occupant's lower legs, respectively. Furthermorethe tuning of the compression load characteristic of each projection forimplementing the aforementioned desired shock absorption characteristicbecomes easy.

Further, according to the shock absorption pad, wherein the first andsecond shock absorption parts are formed from a foam-molded element andare formed by one of multi-layering foam-molded elements, laminatingfoam-molded elements with an adhesive, and an integral foam-molding, itbecomes possible to advantageously absorb the respective shocks overoccupant's lower legs, respectively, with a simple arrangement. In thecase of adopting an integral foam-molding process among others, since itis possible to integrally foam-molding the shock absorption pad in ametallic mold, the shock absorption pad with the aforementioned desiredshock absorption characteristic can be produced in volume at low cost.

Additionally, in the case of the shock absorption pad being afoam-molded component made from a styrene modified polyethylene resin,advantageous effects resulting from the characteristic peculiar tostyrene modified polyethylene resin, such as outstanding dimensionalstability and form retention characteristic, good shock absorptioncharacteristic, and the characteristic of being difficult to generatewear powder and undesired noise against rubbing, can be gained.

Other objects, features and advantages of the present invention willbecome more apparent from the following detailed description when readin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional view for diagrammatically illustrating theassembled state of the shock absorption pad 10 according to the presentinvention.

FIG. 1B is a perspective view for illustrating the assembled state ofthe shock absorption pad 10 in more detail.

FIG. 2A is a plan view of the shock absorption pad 10 according to thepresent invention.

FIG. 2B is a cross-sectional view taken on the line S—S of FIG. 2A.

FIG. 3 is a diagram for showing a test result as to a shock absorptioncharacteristic of the shock absorption pad 10 according to the presentinvention.

FIG. 4 is a diagram for showing the load data on a time series picked upat the lower leg portion of a dummy through a real vehicle crashexamination.

FIG. 5A is a diagram for illustrating the state of the deformed vehiclebody at the first impact.

FIG. 5B is a diagram for illustrating the state of the deformed vehiclebody at the second impact.

FIG. 6A is a plan view for showing the shock absorption pad 90 as acontrast for the shock absorption pad 10 according to the presentinvention.

FIG. 6B is a cross-sectional view of the shock absorption pad 90 takenon the line S—S of FIG. 6A.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereafter, the preferred embodiments according to the present inventionare explained with reference to the drawings.

FIG. 1A is a cross-sectional view for diagrammatically illustrating theshock absorption pad 10 according to the present invention, which isassembled in a vehicle body in place, seen from the vehicle side. FIG.1B is a perspective view for illustrating the installed shock absorptionpad 10 in more detail.

The shock absorption pad 10 is disposed on a toe board 12 that extendsforward and upward in a slanting direction from the front end of thefloor panel 11 (arrow X shown in FIG. 1A indicates the front direction).The toe board 12 defines an inclined area (hereafter, this inclined areais referred as “foot-placing area”) on which occupant's legs 70 are tobe placed, as shown in FIG. 1A. Generally, the shock absorption pad 10is placed in the above-mentioned foot-placing area of the toe board 12and attached to the toe board 12 with clips, etc. Generally, the shockabsorption pad 10 is covered with a floor carpet 13 on which occupant'slegs 70 are to be placed directly.

FIG. 2 is a diagram showing the shock absorption pad 10 according to thepresent invention, wherein FIG. 2A is a plan view of the shockabsorption pad 10, and FIG. 2B is a view taken on line S—S of FIG. 2A.It is noted that the shock absorption pad 10 shown in FIG. 2A has anoutside shape different from that of the shock absorption pad 10 shownin FIG. 1B.

As shown in FIG. 2B, the shock absorption pad 10 according to thepresent invention has a first shock absorption layer 20 on the side onwhich occupant's legs 70 are put, and has a second shock absorptionlayer 30 on the toe board 12 side. These shock absorption layers 20 and30 may be integrally formed from synthetic resin foam, such aspolystyrene-based resin, polyethylene-based resin, polypropylene-basedresin, polyester-based resin, and styrene modified polyethylene resin,or flexible material, such as urethane and rubber.

However, the shock absorption pad 10 is preferably formed from styrenemodified polyethylene resin. Styrene modified polyethylene resin isobtained by impregnated polymerization of the styrene system monomerwith a polyethylene system resin particle. Styrene modified polyethyleneresin contains a styrene ingredient in the range from 40 to 90 wt %,more preferably, contains a styrene ingredient in the range from 50 to85 wt %, most preferably contains a styrene ingredient in the range from55 to 75 wt %.

Here, the foam-molded component made of styrene modified polyethyleneresin has an advantage over the foam-molded component made ofpolyethylene based resin or polypropylene based resin in terms ofdimensional stability and form maintenance characteristic because of thegeneral characteristics of styrene modified polyethylene resin.Moreover, when compared under the same condition of an expansion ratio,the foam-molded component made of styrene modified polyethylene resincan absorb a large amount of shock. Furthermore, unlike the foam-moldedcomponent of polystyrene based resin, the foam-molded component ofstyrene modified polyethylene resin resists becoming brittle and thuscannot break easily. Furthermore, the foam-molded component of styrenemodified polyethylene resin generates neither an undesired noise norwear powder due to rubbing.

Therefore, the styrene modified polyethylene resin which has the aboveadvantageous characteristics is considered as a suitable material forthe shock absorption pad 10, since the shock absorption pad is requiredto demonstrate the effective shock absorption characteristic in alimited thickness and a limited size and is disposed at the floorportion in the cabin on which occupant's legs are put.

The first shock absorption layer 20 of the shock absorption pad 10includes a plurality of projections 24 formed on the second shockabsorption layer 30. These projections 24 are formed within the areacorresponding to the above-mentioned foot-placing area, and arepreferably formed substantially all over the area corresponding to thefoot-placing area. As shown in FIG. 2A, these projections 24 may bearranged in a lattice pattern so as to form channels in the shape of across when seen from above. In addition, these projections 24 may bearranged at regular interval spacing where each projection 24 is spacedfrom its adjacent projection 24 at a constant distance. Further, theseprojections 24 may be arranged in a staggered configuration by makingeach of projections 24 staggered in a longitudinal or lateral direction.

Moreover, each of these projections 24 may have various outside shapes,such as a square, a rectangle, a circle, an ellipse, etc. Moreover, eachprojection 24 does not need to have a constant cross-section along theprojection direction. Furthermore, the tip of each projection 24 may beconfigured so that it may be pressed by occupant's soles at a surface ora point.

Moreover, the size and arrangement of each projection 24 may bedetermined so that an occupant's sole can be supported by severalprojections 24. The total area of the projections 24 to be pressed by anoccupant's sole may correspond to 30–60% of a footprint of an averageoccupant, and the area of each projection 24 may be in the range fromabout 200 mm² to about 600 mm². Moreover, projections 24 may have aheight difference locally and the height of some projections 24 may bedifferent from that of other projections 24.

However, the shock absorption characteristic of the shock absorption pad10 is dependent on various factors, such as a material property of theshock absorption pad 10, and the thickness of each shock absorptionlayers 20 and 30. So it should be understood that the shock absorptionpad with outside shape, arrangement, and size, etc., not specified aboveis within the limits of this invention insofar as it has the shockabsorption characteristic as mentioned below.

FIG. 3 is a diagram for explaining the shock absorption characteristicof the shock absorption pad 10 according to the present invention, inwhich a load-distortion curve of the shock absorption pad 10 accordingto the present invention is shown. The load-distortion curves of othershock absorption pads are also shown for contrast. Specifically, theload-distortion curve of the first comparative pad is indicated by abroken line, which first comparative pad is formed from the samematerial as the shock absorption pad 10 according to the presentinvention but doesn't have the projections 24. The load-distortion curveof the second comparative pad is indicated by a chain double-dashedline, which second comparative pad is formed from a material softer thanthe material used for the shock absorption pad 10 according to thepresent invention and doesn't have the projections 24. It is noted thatthese load-distortion curves are based on the measurements made on atest piece of each shock absorption pad using appropriate measuring andtesting equipment. It is also noted that these load-distortion curvesindicate the distortion characteristic of each shock absorption padagainst the compression load along the direction perpendicular to thetoe board 12 (see the direction Z in FIG. 1A).

As shown in FIG. 3, the load-distortion curve (solid line) of the shockabsorption pad 10 according to the present invention changessignificantly at the predetermined distortion level ε_(p). This meansthat the load-distortion characteristic of the shock absorption pad 10according to the present invention varies in a multi-stepped manner (inthis embodiment, a two-stepped manner) at the predetermined distortionlevel ε_(p). That is, the shock absorption pad 10 according to thepresent invention exhibits a shock absorption characteristic which isequivalent to that of the second comparative pad when deformation of thefirst shock absorption layer 20 begins, and exhibits a shock absorptioncharacteristic equivalent to the first comparative pad when deformationof the first shock absorption layer 20 is completed and deformation ofthe second shock absorption layer 30 begins. In other words, with virtueof a plurality of projections 24, the first shock absorption layer 20can have the shock absorption characteristic equivalent to the secondcomparative pad that is formed from comparatively soft material, eventhough the first shock absorption layer 20 is formed from the samematerial as the first comparative pad.

The inventors of the present invention carried out the crash examinationusing a real vehicle equipped with the shock absorption pad 10 in orderto verify the effect of the shock absorption pad 10 equipped with thestep-wise shock absorption characteristic, and obtained the followingresults.

FIG. 4 shows the load data on the time series picked up at the lower legportion of a dummy through the real vehicle crash examination. In FIG.4, time t=0 is the time of the moment the vehicle's front end came intocontact with the barrier. In FIG. 4, the measurement data (dotted line)of the first comparative pad and the measurement data (chaindouble-dashed line) of the second comparative pad are also shown ascontrast. Hereafter, the examination result shown in FIG. 4 will bediscussed with reference to the FIG. 5 that diagrammatically shows thevehicle's deformation process at the time of vehicle crash, and FIG. 3.

When the vehicle crash begins at time t=0, at first the engine room part40 (see FIG. 1A) begins to deform. Then, when the deformation of theengine room part 40 advances gradually, the load on the lower legs ofthe dummy begins to increase. Then, the load on the dummy's lower legsreaches the first peak value at the time t=t1 when the deformation ofthe engine room part 40 has substantially reached its full potential.Hereafter, this crash stage is referred as “first impact”.

As shown in FIG. 4, the load at the first impact is a momentary shockthat is generated over a relatively shorter time interval as comparedwith the load at the second impact that will be described later. Thatis, the time interval from start-up time to fall time of the firstimpact is shorter than that of the second impact. Thus, the energy to beabsorbed at the first impact is less than that at the second impact.

Referring to FIG. 4, at the first impact, the load exerted on thedummy's lower legs is higher in the case of using the first comparativepad than in the case of using the shock absorption pad 10 according tothe present invention or the second comparative pad. Referring to FIG.3, this result can be derived from the fact that at the first impact theload F_(a1) corresponding to the distortion ε_(a1) of the firstcomparative pad is larger than the load F_(b1) corresponding to thedistortion ε_(b1) of the shock absorption pad 10 according to thepresent invention or the second comparative pad. On the other hand,there is substantially no difference in the load exerted on the dummy'slower legs between the case of using the shock absorption pad 10according to the present invention and the case of using the secondcomparative pad. This result can be derived from the fact that there issubstantially no difference in distortion level between these shockabsorption pads at the first impact.

It can be understood from this test result that the deformation of thefirst comparative pad cannot follow the instantaneous load at the firstimpact and causes a large load to be transmitted to the dummy's lowerlegs. To the contrary, the shock absorption pad 10 according to thepresent invention can deform instantaneously in response to theinstantaneous load at the first impact and thus can effectively reducethe load to be transmitted to the dummy's lower legs.

Subsequently, after the deformation of the engine room part 40 iscompleted, the toe board 12 begins to be pushed up and backward, asshown in FIG. 5B. That is, the toe board 12 begins to deform and movesuch that the sole of a dummy is pushed up. At this time, as the amountof movement of the whole vehicle decreases by the end of deformation ofthe engine room part 40, the dummy moves forward with respect to thevehicle due to its inertial force. That is, the dummy moves forward withits sole abutted against the toe board 12. Because of these two effects,the load of the dummy's lower legs increases gradually and reaches thesecond peak value at the time t=t2. Hereafter, this crash stage isreferred as “second impact”.

The time interval from the beginning of this second impact to its end islonger than the time interval related to the aforementioned firstimpact. Thus, the energy to be absorbed at the second impact is muchgreater than that at the first impact.

Referring to FIG. 4, at the second impact, the load exerted on thedummy's lower legs is greater in the case of using the secondcomparative pad than in the case of using the shock absorption pad 10according to the present invention or the first comparative pad.Referring to FIG. 3, this result can be derived from the fact thatbecause the second comparative pad absorbs the smallest amount of energywhen compared under the same condition of an amount of deformation, ithad already deformed beyond its full potential (i.e. its distortionlevel had reached approximately ε_(max) indicated in FIG. 3) beforeabsorbing all the energy that should be absorbed by the time t=t2. Thatis, the second comparative pad had entered a state where it cannotdeform any more by the time t=t2, and thus the sole of a dummy hadsubstantially entered a state where it was in contact with the rigidbody by the time t=t2.

On the other hand, at the second impact, there is substantially nodifference in the load exerted on the dummy's lower legs between thecase of using the shock absorption pad 10 according to the presentinvention and the case of using the first comparative pad. Referring toFIG. 3, this result can be derived from the fact that the load F_(a2)corresponding to the distortion ε_(a2) of the first comparative pad atthe second impact is substantially equal to the load F_(b2)corresponding to the distortion ε_(b2) of the shock absorption pad 10according to the present invention at the second impact.

From the above test result, it can be said that the shock absorption pad10 according to the present invention can achieve the lowest values ofload exerted on the dummy's lower legs both at the first impact and atthe second impact and protect occupant's lower legs most effectively.This is because at the first impact in which the instantaneous load isgenerated, the occupant's lower legs are protected by the first shockabsorption layer 20, which can easily deform and absorb a small amountof energy per unit area (which unit area includes the area of the firstshock absorption layer 20 not provided with projections 24), while atthe second impact in which a relatively long-duration load is generateddue to the upward movement of the panel in the foot-placing area, theoccupant's lower legs are protected by the second shock absorption layer30, which absorbs a relatively large amount of energy per unit area.Thus, according to the shock absorption pad 10 according to the presentinvention, since it has the shock absorption characteristic that variesin stages according to the first impact and second impact which occur instages in the course of the vehicle crash process, it becomes possibleto protect occupant's lower legs effectively.

It is noted that the thickness of the first shock absorption layer 20,the number and arrangement of projections, etc., are determined so thatthe energy at the first impact can be absorbed only by the deformationof the first shock absorption layer 20, while the thickness and area,etc., of the second shock absorption layer 30 are determined so that thesecond shock absorption layer 30 cannot deform beyond its maximum levelat the second impact (i.e. so that the amount of deformation of thesecond shock absorption layer 30 cannot reach the elastic limit).However, it is also noted that the overall thickness of the shockabsorption pad 10 will be subjected to the constraint from the viewpointof sufficient cabin space.

The shock absorption pad 10 used for the above-mentioned test had athickness of about 30 mm, the thickness of the first shock absorptionlayer 20 was about 10 mm, and the total area of the top surfaces of theprojections 24 was about 55% of the total area of the shock absorptionpad 10. This shock absorption pad 10 showed the desired shock absorptioncharacteristic. That is, during the first impact the shock absorptionpad 10 exhibited the shock absorption characteristic equivalent to thefirst comparative pad, and at the time at which the second impact began(i.e. the time t=t3 in FIG. 4) it deformed at the distortion revelε_(p), which corresponds to the transition point of the shock absorptioncharacteristic, and during the second impact it exhibited the shockabsorption characteristic equivalent to the second comparative padwithout deforming beyond its maximum level. However, these designmatters depend on the amount of energies to be absorbed at the first andsecond impact and thus depend on the structure of the vehicle body. Theshock absorption characteristic of the shock absorption pad 10 may beadjusted based on a real crash test, analysis, etc., for every type ofvehicle to implement the aforementioned desired shock absorptioncharacteristic.

Here, since the shock absorption pad 10 according to the presentinvention has a plurality of projections 24 formed in a discrete pattern(i.e. spaced arrangement) as mentioned above, and further has the firstshock absorption layer 20 on the side of occupant's legs 70, theadjustment of the shock absorption characteristic for realizing theaforementioned desired characteristic becomes easy and problems arisingfrom normal use can be avoided.

On the contrary, with reference to FIG. 6A and FIG. 6B, the shockabsorption pad 90 equipped with the protruding lines 93 formed in acrisscross pattern is shown. The first shock absorption layer 91 of thisshock absorption pad 90 has higher in-plane rigidity as compared withthe first shock absorption layer 20 of the present invention equippedwith projections 24 not connected with each other in a plane over thefoot-placing area, and thus the adjustment of the shock absorptioncharacteristic of the shock absorption pad 90 for realizing theaforementioned desired characteristic becomes complicated. That is, thedeformation of the portion of the protruding lines 93 that actuallyabuts against the sole involves the deformation of the other portionthat actually doesn't abut against the sole. So the adjustment of theshock absorption characteristic should be done considering such adeformation characteristic. Furthermore, with such high in-planerigidity, the first shock absorption layer 91 cannot deform in a goodfollow-up manner against an instantaneous load such as theabove-mentioned first impact load.

Similarly, in the case of the shock absorption pad 95 (not shown)equipped with the first shock absorption layer 20 on the side of the toeboard 12 instead of on the side of the occupant's leg 70, the adjustmentof the shock absorption characteristic of the shock absorption pad 90for realizing the aforementioned desired characteristic becomescomplicated because all the projections 24 abut against the surface ofthe toe board 12. That is, the pressure on the shock absorption pad 95from the sole causes the deformation of substantially all theprojections 24 and furthermore there may be a difference in the amountof the deformation between each projection 24. So the adjustment of theshock absorption characteristic of the shock absorption pad 90 forrealizing the aforementioned desired characteristic becomes verydifficult. Moreover, in the case of realizing the aforementioned desiredcharacteristic, since the compression load per unit projection becomessmall, the projections 24 may easily become flat when the occupant'slegs 70 press strongly them or when the occupant's legs 70 are placedonly on them. In this case, the shock absorption pad 95 will not fullyachieve its function in the actual crash because of the flattenedprojections 24. Moreover, such a shock absorption pad 95 isn't likely tokeep its shock absorption characteristic for a long time and thus doesnot have good durability.

In contrast to this, the shock absorption pad 10 according to thepresent invention, which is equipped with projections 24 not connectedwith each other, has the structure in which only some projections 24which are actually supporting the sole can deform. So the desired shockabsorption characteristic is realizable with easy adjustment, setting upa suitable compression load per unit projection so as not to cause theprojections 24 to deform easily during normal use.

Further, the present invention is not limited to the above-describedembodiments, and variations and modifications may be made withoutdeparting from the scope of the present invention.

For example, in the above-mentioned embodiments, although the shockabsorption pad 10 according to the present invention is molded in onepiece to have the first shock absorption layer 20 and the second shockabsorption layer 30, the shock absorption pad 10 may be constituted byforming each shock absorption layer from a different material and bylaminating together these shock absorption layers.

In addition, the shock absorption pad 10 according to the presentinvention may be constituted by forming each shock absorption layer fromthe same material with different density and by laminating togetherthese shock absorption layers, or may be constituted by laminatingtogether foam-molded absorption layers made from the same kind of or adifferent kind of synthetic resin. Furthermore, the shock absorption pad10 according to the present invention may be an integrally-moldedcomponent made by expanding the same kind of or a different kind ofsynthetic resin foaming beads with a different expansion ratio in ametal mold. Although reference is made to the two-stage shock absorptioncharacteristic in the above-mentioned embodiment, it is also possible torealize a three or more stage shock absorption characteristic by formingadditional shock absorption layers.

1. A shock absorption pad for a vehicle which is attached on a surfaceof a toe board and on which an occupant's foot is placed, comprising: afirst shock absorption part provided on the occupant's foot-placing sidefor absorbing an impact force generated in a boundary region at which anenergy absorption load of a vehicle body becomes different in adeformation process of the vehicle body at a vehicle crash, the firstshock absorption part being divided in a plane over the occupant'sfoot-placing area to lower an in-plane rigidity of the first shockabsorption part during a compressive deformation; and a second shockabsorption part provided facing the toe board for absorbing an impactgenerated in a region in which the energy absorption load is high,wherein an energy absorption load per unit area of the first shockabsorption part is lower than an energy absorption load per unit area ofthe second shock absorption part.
 2. The shock absorption pad for avehicle as claimed in claim 1, wherein the first shock absorption partis comprised of a plurality of projections formed all over theoccupant's foot-placing area on an upper surface of the second shockabsorption part.
 3. The shock absorption pad for a vehicle as claimed inclaim 2, wherein the first and second shock absorption parts are formedfrom a foam-molded element and are formed by one of multi-layeringfoam-molded elements, laminating foam-molded elements with an adhesive,and integral foam-molding.
 4. The shock absorption pad for a vehicle asclaimed in claim 2, wherein the shock absorption pad is a foam-moldedcomponent made from a styrene modified polyethylene resin.
 5. The shockabsorption pad for a vehicle as claimed in claim 1, wherein the firstand second shock absorption parts are formed from a foam-molded elementand are formed by one of multi-layering foam-molded elements, laminatingfoam-molded elements with an adhesive, and integral foam-molding.
 6. Theshock absorption pad for a vehicle as claimed in claim 1, wherein theshock absorption pad is a foam-molded component made from a styrenemodified polyethylene resin.
 7. A shock absorption pad for a vehiclewhich is attached on a surface of a toe board and on which an occupant'sfoot is placed, wherein the shock absorption pad is a foam-moldedcomponent made from a resin and is provided with a plurality ofprojections on the occupant's foot-placing side, said projections beingspaced from each other in a plane over the occupant's foot-placing areato lower an in-plane rigidity of the shock absorption pad on theoccupant's foot placing side during a compressive deformation.
 8. Avehicle, comprising a toe board and a shock absorption pad, the shockabsorption pad comprising: a first shock absorption part provided on anoccupant's foot-placing side for absorbing an impact force generated ina boundary region at which an energy absorption load of a vehicle bodybecomes different in a deformation process of the vehicle body at avehicle crash, the first shock absorption part being divided in a planeover the occupant's foot-placing area to lower an in-plane rigidity ofthe first shock absorption part during a compressive deformation; and asecond shock absorption part provided facing the toe board for absorbingan impact generated in a region in which the energy absorption load ishigh, wherein an energy absorption load per unit area of the first shockabsorption part is lower than an energy absorption load per unit area ofthe second shock absorption part.